The present invention relates to a method for controlling fungal disease in plants, to novel antifungal compositions, and to compounds useful for controlling fungi which attack agricultural and garden plants and seeds. More particularly, the invention relates to the use of a selected mono-5-substituted-3-chloro-4H-1,2,6-thiadiazin-4-one as an antifungal agent for controlling fungal disease in plants.
Geevers and Trompen disclosed the preparation 3,5-dichloro-4H-1,2,6-thiadiazin-4-one and its use as an intermediate to prepare various other 5-substituted-3-chloro-4H-1,2,6-thiadiazin-4-ones including the 5-phenylthio and 5-methylthio derivative. J. Geevers and W. P. Trompen, Rec. Trav. Chim., 93, 270 (1974). The 5-phenoxy derivatives are disclosed in U.S. Patent Application Ser. No. 728,860 filed of even date herewith.
While the 5-phenylthio and 5-methylthio derivatives and the method for preparing them have been disclosed, the reference provides no indication of any biological activity. More particularly, there is no suggestion that the compounds of this invention have antifungal activity.
It has now been found that selected mono-5-substituted 3-chloro-4H-1,2,6-thiadiazin-4-ones, which are hereinafter described, exhibit excellent antifungal activity and are useful in providing control of fungal disease in agricultural crops by foliar, seed, and soil application.